They flew in on the lake breeze in mid-May to mid-June, hordes of mayflies swarming Point Place and other coastal spots. They covered windows, buildings, sidewalks, and windshields, their carcasses piling up on sidewalks and roads — sometimes 5 inches deep. Cars slid on the slimy mess, crashing into trees, poles, and other cars to the point that firefighters had to hose down the streets. All but essential lights had to be doused, and every morning workers shoveled waste to be hauled to dumping grounds. Dust from their disintegrating shells caused allergic reactions in sensitive people, dubbed Mayfly Fever.